Objections to planning applications often allege shortcomings in the environmental impact assessment (EIA) process, or failure to carry out EIA. Those allegations can be a key part of any legal challenge to consent granted for the project. The law on EIA continues to evolve through the decisions by the courts on those challenges.

Recent court cases have clarified the legal position on screening; when is the right time for impacts to be addressed, and how far indirect impacts should be taken into account.

Screening and purposive interpretation

Screening is the process for identifying whether EIA is required (but the environmental impacts are still taken into account in the consenting decision even if there is no EIA).

The applicable threshold often depends on the relevant project type, as listed in the EIA Regulations.

In Swire v Ashford BC, the issue was whether the planning authority were correct to treat a winery as an urban development project. The objector argued it should have been treated as "packing and canning of animal and vegetable products" or "brewing and malting".

The court acknowledged that a purposive approach is taken to interpreting the EIA Regulations, but rejected the objector's approach as going too far:

“[the Regulations] 'have a wide scope and a broad purpose'. That is commonly cited and often misunderstood; it speaks against a legalistic approach and requires instead a purposive approach; it does not turn a word into meaning whatever can be extruded from it.”

Screening – when?

In Swire, the judge acknowledged it is in the nature of screening opinions that they are usually provided at an early stage and on incomplete information.

The issue in that case was the legal status of a negative opinion, ie. a screening opinion which concludes that the development does not require EIA.

The judge confirmed that a negative opinion is not final. At the time of granting planning permission, the planning authority must still ask itself whether the development is likely to have significant environmental effects. If the answer is "yes", the Regulations prevent permission from being granted until EIA is undertaken.

That is consistent with the general principle in planning decisions that it is the policies and other material considerations at the time of the decision which must be taken into account, not those when the application was submitted.

The judge made it clear that the planning authority cannot just change its position: there must be a change in circumstances or an "important misapprehension".

Unfortunately for the objector, there had been no change in circumstances, merely a difference of view on landscape and visual effects.

Screening – relevance of consent conditions

The Champion case confirmed that proposals for remediation or mitigation measures can be taken into account when deciding if EIA is required, ie. the likelihood of significant effects.

The limits of that principle are illustrated by the court decision in another case brought by Ms Swire, this time challenging the grant of permission for 20 houses on the site of a former animal carcass rendering facility. It had been licensed for the disposal of cattle infected by BSE.

It was common ground that the site was contaminated. A comprehensive remediation scheme would be required.

The judge held that, to make an informed judgment that the development would not be likely to have significant effects on the environment, the screening authority must have sufficient evidence of the potential adverse environmental impacts and the availability and effectiveness of the proposed remedial measures.

For this site there was very little evidence of safe and effective methods of detecting, managing and eliminating the potential contamination, and a lack of sufficient information to assume measures would be successful. Accordingly, the decision that EIA was not required was vitiated by a legal error.

Deferring consideration of significant impacts

Consent conditions are a means to defer discussion of the detail of mitigation. The Pearce v Secretary of State case involves a more fundamental issue of whether consideration of a significant impact can be deferred for later decision.

Pearce challenged the decision of the Secretary of State to grant a development consent order on 1 July 2020 for the Vanguard offshore wind farm.

The environmental statement identified a significant cumulative landscape and visual impact arising from the onshore substation, which was also to serve the proposed Boreas offshore wind farm. The court described that impact as an "important controversial issue".

The Secretary of State decided that it was appropriate for cumulative impacts to be considered in any future examination into the Boreas offshore wind farm, rather than in the Vanguard application. The Boreas examination was on-going when the Vanguard consent was granted.

The court disagreed. The Regulations require the decision-maker to evaluate and weigh the significant effects. That cannot be deferred to the decision on a different project.

Indirect impacts

The Regulations require the EIA process to consider direct and indirect effects of the development. In the Finch v Surrey CC case the issue for the court was how far indirect effects need to be considered.

Ms Finch challenged the grant of planning permission for oil wells for the production of hydrocarbons. The ES assessed the greenhouse gases that would be produced from the operation of the development itself. The legal challenge concerned the non-assessment of the greenhouse gases that would be emitted when the crude oil was used by consumers, typically as a fuel for motor vehicles, after being refined elsewhere.

The court held that EIA only assesses effects which the development itself has on the environment, and not the environmental effects which result from the consumption, or use, of an end product.


Two decisions resulted in consents being quashed (Swire, Pearce). Those can be seen as "firing a warning shot", although the decision-makers in each case struggled to justify their approach.

The other two legal challenges were unsuccessful (Swire, Finch). Those "apply brakes", with the judges not being prepared to take a wide interpretation of the Regulations.